The invention relates to a caulking accessory for use with a caulking cartridge and caulking gun, the accessory being particularly adapted for sealing cracks in concrete or other surfaces.
A caulking cartridge for use with a conventional caulking gun comprises a cylindrical tube containing a plastic sealant material, and a nozzle or spout extending axially from an end face of the tube. For normal use the caulking cartridge is inserted into the caulking gun, and the nozzle is cut obliquely at an appropriate location to provide an obliquely cut tip of a size sufficient to produce a sealant bead of a desired size for the crack or cavity to be filled. This simple approach has many limitations and there are many patents disclosing devices which cooperate with the conventional caulking cartridge nozzle to simplify application of the sealant, and/or to improve the resulting application of sealant.
U.S. Pat. No. 5,017,113 (Heaton et al.) discloses a filleting attachment for a conventional caulking gun for use in corners. The nozzle of the conventional cartridge is cut and then inserted in a complementary tapered nozzle of the attachment to discharge sealant into the attachment. The attachment has an integrally moulded triangular shaped plate as a distal end thereof which engages walls of a 90 degree corner so as to guide the nozzle and simultaneously to shape the bead of sealant discharged from the nozzle. The attachment has a simple annular end flange for fitting between a generally annular end flange of the conventional caulking gun and an end face of the caulking cartridge.
U.S. Pat. No. 4,946,081 (Jacobson) discloses an applicator for a sealant cartridge having a discharge nozzle with a semi-cylindrical tubular portion disposed perpendicularly to a distal end of the nozzle. The tubular portion has an open end to discharge excess sealant therethrough to provide a flow indicator ensuring adequate filling of the crack. The applicator is screw-threaded onto a sleeve extending from the outer face of the cartridge, and thus is specifically adapted for use with a cartridge having complementary threads or an interference fit, or other means of securing the applicator to the opening of the sealant cartridge.
The nozzles of common, conventional sealant cartridges are generally similar in size and taper, and thus many of the applicators or accessories designed to be used with such cartridges tend to rely on an interference fit between the applicator or accessory and the cartridge nozzle. It is often difficult to maintain an adequate seal using an interference fit, and thus inadvertent sealant leakage can occur between the nozzle and the applicator, especially if higher sealant pressure than normal is attained. Also, to attain adequate penetration of sealant into deep cracks, is advantageous to generate high sealing pressures, but these higher pressures cannot be attained if excessive leakage occurs between the nozzle and the applicator. Also, some prior art caulking accessories are attached to the caulking gun and cartridge in a relatively loose manner which can result in inadvertent displacement between the accessory and nozzle, further aggravating sealant loss. Also, sealant can inadvertently leak between a rough surface with the crack and the applicator
Thus there is a need for a caulking applicator or accessory which can be used with conventional caulking guns and cartridges, and that provides an adequate seal with the cartridge nozzle to permit attainment of relatively high pressures for injecting sealant into relatively deep cracks.
In contrast with the two patents disclosed above which disclose devices for conventional, relatively small size caulking cartridges, U.S. Pat. No. 4,986,862 (Matsufuru) and U.S. Pat. No. 5,186,949 (Lai) both disclose sealant applicators for use with larger, industrial-sized sealant containers which commonly use an injector to discharge sealant under relatively high pressure into the applicator for subsequent injection into a crack. A distal portion of the application in both these devices has a flat flange adapted to contact the surface containing the crack, the flange enclosing the crack so as to limit discharge of sealant from the crack until the crack has been substantially filled. Both these devices are relatively complex and require specialized equipment and would not be appropriate for use with conventional caulking guns and cartridges.